The present invention generally relates to an internal combustion engine and more particularly to a hybrid internal combustion engine where heat energy is reused to heat and compress a fluid, which is injected into the engine to increase the fuel efficiency thereof.
Internal combustion engines use a repeating cycle of intake, compression, combustion and exhaust to convert air and fuel into mechanical energy. The mechanical energy may be used to move a vehicle or may be converted to other forms of energy, such as, electricity. Only a small amount of energy is extracted from the combustion process and waste energy in the form of heat is radiated from the engine and out the exhaust. In order to dissipate the heat generated by the engine, a heat exchanger, generally known as a radiator, and/or other cooling systems may be employed. The radiator may contain a coolant, usually water mixed with anti-freeze (ethylene glycol). The coolant may be pumped through the engine compartment and may extract heat from the engine. Cooler outside air may pass over the heated coolant which may lower the temperature of the coolant by carrying the heat away as it passes over the radiator and away from the vehicle. The coolant may be pumped back through the engine compartment to extract heat in a continuous process. The heat radiated from the engine and/or extracted through use of a radiator or similar cooling system is wasted energy, which leads to greater fuel consumption.
Many efforts have been used to reduce the fuel consumption of the conventional automobile internal combustion engine. Alternative fuels have been considered. The “hybrid engine” may use a conventional internal combustion engine with at least one electric motor/generator. The electric motor/generator may operate the vehicle at low power settings and the internal combustion engine may operate the vehicle at high power settings. The “hybrid engine” may use regenerative braking by capturing kinetic energy normally lost during braking to charge the batteries, a process usually performed by an alternator, thus using less power and lowering fuel consumption.
The hybrid engine has increased fuel efficiency of modern internal combustion engines but greater efficiency is still desired. Exemplary embodiments of the present invention may utilize heat, normally wasted in known internal combustion engines, to heat a fluid. The fluid may be maintained at a high temperature and under pressure. Since the fluid may be maintained under pressure and at a high temperature, when the fluid is injected into a cylinder, it may immediately expand thus driving the piston back down. While the expanding fluid may give less power than a typical combustion stroke, controls may be put in place to allow fluid injection strokes to be used in place of combustion strokes when high power may not be required, such as when driving across a flat surface or as in the case of a generator, during low power demands such as during the night.